JPH0712394B2 - Drives for automatic washing machines - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stirrer drive for use in an automatic washing machine with an alternating reversing drive motor.

2. Description of the Prior Art U.S. Pat. No. 4,542,633 discloses a stirring type washing machine having a stirring wheel connected to a reversible drive motor via a pulley transmission. The stirring wheel is shown as a wheel with short wall thickness blades. In a motor described as having high hardness, a rotation angle detector is connected to a controller for rotating a stirring wheel over a predetermined angle. When the predetermined angle is reached, the electric motor is de-energized until the stirring wheel is stopped, and when the stirring wheel is stopped, the electric motor is reversed in the opposite direction, so that the stirring wheel is again rotated by the predetermined angle. It can be rotated.

The agitator range in automatic washing machines, manufactured by the assignee of U.S. Pat.No. 4,542,633 and believed to embody the teachings of the above U.S. patent, is approximately 70% per minute at each range. It was observed to be 360 °. The high-hardness motor maintains a substantially constant agitator speed in each rotational direction following a short rapid acceleration, followed by coasting to a stop.

As described above, an automatic washing machine drive device having a reversing motor that generates a substantially rectangular wave stirring curve is known. The stirring curve is defined here as the rotational speed of the stirrer as a function of time. Therefore, the square wave agitation curve represents a constant velocity in one direction followed by a constant velocity in the opposite rotational direction. Thus, if the stirrer is gradually accelerated in each direction of rotation and then immediately gradually decelerated, a sinusoidally shaped stirring curve will be obtained.

U.S. Pat. No. 3,315,500 to Brundage et al. Discloses a drive for an agitator that uses an electric motor that operates at a constant speed in one direction to drive a hydraulic transmission. And according to this device,
A very rapid reversal of the stirrer takes place via the reversing valve, so that a square-wave-shaped stirring movement also takes place with this drive. Therefore, an elastic joint is used between the stirrer and the stirrer drive shaft to reduce the impact that would otherwise be applied to the stirrer at each inversion. still,
In this US patent, a rectangular wave stirring motion is preferred because a large amount of energy is applied to the washing load.

U.S. Pat. No. 4,232,536 discloses an automatic washing machine equipped with an induction motor having an axial gap. The motor is iteratively inverted to oscillate the vertical shaft type agitator via a planetary gear drive coupled between the motor and the vertical shaft agitator, and the motor is operated at high speed. It It has been recognized that it is desirable to provide a soft starting action for the stirrer each time the stirrer is inverted, where the soft starting action is provided by backlash in the planetary gear drive. However, there is no mention in the above U.S. patent of the resulting agitator action.

U.S. Pat. No. 4.555.919 discloses a stirrer with flexible vanes for use in high-threshold washer. This stirrer has a high degree of coupling to the wash load.

It has been found that sinusoidal agitator motion in a washing machine provides improved washing properties, reduces damage to the fabric and / or reduces stretch of knitted or other delicate articles. . However, such agitator movements have heretofore been unrealizable without the use of a relatively large, complex and expensive reversing transmission between the unidirectional motor and the agitator.

SUMMARY OF THE INVENTION In the automatic washing machine drive device of the present invention, substantially a sinusoidal stirrer motion is generated even when a start-up steep start and stop drive signal is input to the drive mechanism, which is improved at low cost. The washing action is performed. This is achieved firstly by a tuned motor-drive-stirrer system with a high starting low slip torque motor. The drive mechanism couples the high slip electric motor to an agitator provided in the clothes basket of the automatic washing machine and the control means drives the electric motor first in the first direction and then in the opposite direction. To provide abrupt start and stop control pulses. This control pulse is in the form of a modulated square wave.

The electric motor has a low starting torque so that it makes a soft start each time it is turned on with a control pulse. The control pulses are mutually exclusive so that the next control pulse does not stop the motor before starting it in the opposite direction, but gives the motor an off period that is long enough to reduce its speed. It is separated. A deceleration drive can be used to connect the electric motor to the agitator. On the other hand, the stirrer is "coupled" to the load. However, the deceleration drive is not required in all embodiments. The stirrer is an energy absorbing stirrer with flexible vanes that couple its movement to water as well as to the laundry load. With the rotational moment of the electric motor and the stirrer coupled to the load, the stirrer speed is gradually reduced each time the electric motor is turned off.

When the first control pulse is received by the motor drive,
With the gradual activation of the electric motor in one direction, the stirrer begins to rotate in the first direction until the predetermined speed is reached. When the predetermined speed is reached, the pulse ends, the motor is shut off, and the agitator slows or "coasts". Before or at the time the stirrer is stopped, the motor drive receives a second control pulse. This second control pulse causes the motor to start driving the agitator in the opposite direction. The energy-absorption agitator, in combination with the high-slip motor and the reduction drive, smooths the transients or transitions that intervene between the direction reversals, thus making the modulated square-wave control pulse input approximate the agitator. A sinusoidal output is generated at. Approximately smoothing the agitation curve to a sinusoidal motion curve and setting the agitator range speed and angle when interacting the motor speed / torque characteristics with the pulse timing motor-agitator deceleration characteristics and clothing load. This is achieved by equilibrating or matching the geometrical factors of the stirrer.

As described above, the anti-invention proposes a low-cost and efficient stirrer drive device that does not require an expensive and complicated inversion transmission device, and yet generates desired washing characteristics at an optimum stroke speed and stroke angle. is there.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1, reference numeral 10 generally designates a vertical shaft agitation washing machine, the washing machine undergoing a series of programmed washing, washing and high speed spinning steps. It is equipped with a presettable control unit for automatically operating the machine.
In addition, the washing machine is provided with a frame 12, and by this frame 12,
Panel 14 forming the sides, top, front and back of box 16.
Is carried. A lid 18 is provided that is hinged in a conventional manner to allow access to the interior of the washing machine 10. The washing machine 10 has a back console 20 on which manually settable control means including a timer dial 22 and a temperature selector 24 are arranged.

Inside the washing machine 10, a non-perforated tub 26 for containing a liquid is arranged, and in the tub 26, a perforated basket 28 is attached so as to be rotatable around a vertical axis. The agitator 30 arranged in the vertical position is operatively connected to the electric motor 32 via the drive mechanism 34.

Referring to FIG. 2, the stirrer 30 is connected to the reduction drive unit 34 by a shaft 36. On the other hand, the drive unit 34 is driven by the electric motor 32 via the pulley mechanism 38. The electric motor 32 is
It is preferably a high slip motor, and more preferably a fixed split capacity (PSC) type motor having a starting torque that is low compared to the stopping torque so that the stirrer can be flexibly started. The PSC motor 32 is a motor having a relatively flat load characteristic curve above the yield point so that the steady-state speed does not vary significantly with load. The electric motor 32 is attached to bracket structures 40 and 42 which are connected to the frame 12 of the washing machine 10.

The electric motor 32 is connected to the reduction drive unit 34 by a pulley mechanism 38 including a drive pulley 44 and a driven pulley 46 connected by a belt 48. In one embodiment, the speed reducer drive 34 comprises a planetary gear transmission including a planetary gear housing 52 and a spring clutch 50 mounted within a speed reducer drive frame 54 connected to the frame 12. . It should be noted that although a planetary gear reduction drive is disclosed herein for use in connection with the present invention, it is also possible to utilize various other reduction transmission mechanisms as is well known to those skilled in the art. Please understand. Also, omitting the deceleration drive unit,
It is also possible to connect directly to an appropriately selected electric motor.

The shaft 36 extends upward from the reduction drive unit 34 through the tank 26 and the perforated basket 28 and is connected to the agitator 30. A vat ring 55 extends around the top of vat 26. The stirrer 30 is a backward stirrer and includes an upper body portion 56 having a spiral blade 58 and a lower stirrer portion 60, and a plurality of flexible blades 62 are provided from the lower stirrer portion 60. Is protruding. These flexible blades 62 allow the stirrer 30 to absorb energy as the direction of rotation is reversed, keeping the stirrer 30 coupled to the water in the tub 26 and the load of clothing in the tub. be able to. The load from this connection between the agitator and the clothes and water causes the motor speed to increase slowly.
In addition, the flexible blades cover the range of clothing load,
It serves to provide more even load coupling and torque over the angular range of the stroke. Further, the flexibility of the blades 62 prevents the impact load at the start of the stroke from changing the fixed rotor torque of the electric motor 32.

The torque / speed characteristics of the PSC motor 32 are shown in FIG. The torque / speed curve 70 is drawn for the first direction of motion, and the curve 72 represents the torque / speed characteristic in the opposite direction. As already mentioned, the relatively flat curve above the breakover or yield point 74 where the motor 32 has a small torque in the low speed region is indicated by the rightmost part of the curve with the maximum torque value. Has been done. It will be appreciated that the PSC motor 32 operates effectively primarily in the starting portion of the torque / speed curve.

Referring to FIG. 4, the electronic control circuit 80 used with the apparatus of the present invention is connected to drive the PSC reversible motor 32 during the wash cycle. The circuit 80 can be roughly divided into three parts, that is, a power supply circuit 82, an output drive circuit 84, and a logic circuit 86, as shown by a dotted line. The power supply circuit 82 is connected to an AC power supply with a lead wire 88, and includes a half-wave rectifier 90, a Zener diode adjusting unit 92, and a filtering capacitor 94.

The output drive circuit 84 includes two pairs of power triacs 96 and 98.
And 100 and 102. Triac vs 96, 9
8, 100 and 102 alternately bias the field of the electric motor 32.
The triacs 96 and 98 are controlled by the transistor amplifier 104 during motor operation in the first direction, while the triacs 100 and 102 are controlled by the transistor amplifier 106 during operation of the motor 32 in the opposite direction. The bases of each of the transistors 104 and 106 are connected to be controlled by the logic circuit 86.

The logic circuit portion 86 of the control circuit 80 comprises a timer 108 for controlling the amount of time the motor 32 is on and the amount of time the motor 32 is off. Output of timer 108
110 is a flip-flop 116 via an inverter 112.
The trigger signal is supplied to the clock input terminal of. Thereby, the flip-flop 116 is triggered on the rising edge of the inverted timer signal. Flip flop 116
Acts as a switch and produces an alternating signal from its outputs 118 and 120 to the two NAND gates 122 and 124. The timer signal from output 110 is also fed to NAND gates 122 and 124 in a non-inverting state, whereby
The NAND gates 122 and 124 decode the outputs of flip-flop 116 and timer 108. Output terminal of NAND gate 122
126 is connected to the base of the transistor 106 of the drive circuit 84, while the output 128 of the NAND gate 124 is connected to the transistor 104.

Transistor 130 and Zener diode 132 are RC element 13
In combination with 4 and 136, it produces an output on conductor 138 after a predetermined period from the first power up, which causes NAND gates 122 and 124 to power drive circuit 84 until timer 108 stabilizes. A time delay is provided to prevent this.

Reference is now made to FIG. 5, which is a signal pulse waveform diagram for the circuit of FIG. 4, which shows the timer trigger signal 140 generated on the timer output conductor 110. The inverted timer signal 142 is generated by the inverter 122 and applied to the clock input 114 of the flip-flop 116.
The flip-flop output signal on conductor 118, shown as signal 144, switches states at each positive transition of the inverted timer signal 142. Also flip-flop 116
Produces a signal 146 on conductor 120 that is the inverse of signal 144. The NAND gate 122 has a timer signal 140 and a flip-flop.
Upon receiving the flop signal 144, a signal 148 is generated based on the flop signal 144, and the signal 148 is supplied to the drive circuit 84. Also, NAN
D-gate 124 is a timer signal 140 and an inverted flip-flop.
It receives flop signal 146 and generates signal 150. This signal
150 is supplied to the drive circuit 84. Signal 148 consists of a series of square wave pulses, while the square wave pulses of signal 150 occur between the signal pulses 148. Therefore, the output of the logic circuit 86 is preferably a series of square wave pulses, with a signalless period between each pulse, which are alternately modulated as inputs to the opposite polarity field of the motor 32. Produces a square wave pulse. Drive circuit 84 and logic circuit 86
There is no feedback between and so in the present invention,
It can be said that open loop control is employed.

FIG. 6 shows a motor speed curve 152 for a motor 32 operating in accordance with the principles of the present invention. The electric motor 32 produces an output which is represented by a curve which is somewhat sinusoidal in shape. Each complete cycle of the motor speed curve of FIG. 6 occurs every 0.96 seconds, resulting in a stirrer 30 stroke count of 63 strokes per minute. Each cycle can be divided into four partial cycles. The first partial cycle of which is shown at 154 and has a duration of 0.3 seconds and represents the motor start phase from zero speed. Every 0.3 seconds, a second stage partial cycle indicated by reference numeral 156
It starts with the disconnection of the electric power from the electric motor 32. This second stage 156 lasts for 0.18 seconds, and it can be seen that the motor gradually slows to near zero speed. In the partial cycle or stage 158, the motor 32 begins to accelerate in the opposite direction for 0.3 seconds. After a predetermined time, power is again disconnected from the motor 32 at step 160 and the motor 23 coasts toward zero speed for 0.18 seconds.
At zero speed, the cycle begins again, producing a generally sinusoidal continuous output with on / off pulse drive of the motor with alternating square wave signals.

FIG. 7 shows a current curve 162 flowing from the feed conductor 88 through the motor 32 for comparison with the motor speed curve 152 of FIG. As is clear from this figure, the electric motor 32 has
During positive and negative acceleration, different windings are supplied with square wave AC power modulated at 60Hz. This AC
Power is interrupted between each direction reversal, which allows the motor to slow down before starting in the opposite direction.
The positive acceleration is done with AC power received by the motor 32 for the duration of the pulse 148, while the negative acceleration is done with the pulse.
This is done with AC power applied to the motor 32 for a duration of 150.

The modulated square wave, designated by the reference numeral 162, has a duration and a dwell period corresponding to the drive characteristics of the electric motor, the speed reducer and the stirrer so that an angle of attack between 120 ° and 230 ° is obtained. In the preferred embodiment, the range angle is between 190 ° and 200 ° and the range number is between 60 and 70 per second. The term "stirrer stroke" as used herein is defined as the stirrer's rotational movement in one direction followed by rotation in the opposite direction to the starting position. Also, the range angle is the rotational movement angle in only one direction.

Referring now to FIG. 8, which shows the agitator speed according to the present invention as curve 170. As is clear from a comparison of the graphs of FIGS. 6 and 8, the agitator motion is further smoothed by the characteristics of the drive mechanism 34 and the flexible blade agitator 30, and the sine wave is closer to a square wave input. Output is obtained.

Although the embodiments disclosed herein have been described as having a PSC motor, the use of other types of motors whose operation can be reversed, such as by reversing the polarity of the applied voltage is also conceivable.

As described above, the high-slip electric motor 32 is coupled to the energy absorption stirrer 30 by the simple drive speed reduction mechanism 34, and the electric motor 32 is supplied with a rectangular wave pulse such as a modulated rectangular wave pulse so that a sinusoidal stirrer motion is generated. An agitator drive for a washing machine 10 driven by a drive circuit supplied is shown and described in the drawings.
As is apparent from this description, no complex transmission is required anymore for converting the unidirectional movement of the electric motor into a sinusoidal stirring movement. In addition, the device of the present invention provides increased efficiency, reduced component wear, and a high level of wash action.

As is clear from the above description, the present invention can be embodied in various modifications and variations that can differ from the above-described configuration in details. Therefore, it should be understood that all the modifications reasonably and properly included in the scope of the present invention are included in the scope of the present invention.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of an automatic washing machine equipped with a drive system based on the principles of the present invention, and FIG. 2 is a sectional view of the automatic washing machine taken along line II-II in FIG. And a washing tub,
FIG. 3 shows the agitator and drive mechanism, and FIG. 3 shows the torque / torque of a high slip drive motor used with the drive mechanism of the present invention.
FIG. 4 is a diagram illustrating speed characteristics in a graph, FIG. 4 is a circuit diagram of a control circuit used with the drive mechanism of the present invention, and FIG.
FIG. 6 is a diagram illustrating a signal pulse waveform generated in the circuit of FIG. 4, FIG. 6 is a diagram illustrating a time change of a drive motor speed of a drive mechanism according to an embodiment of the present invention, FIG. 7 is FIG. 8 is a diagram showing a time change graph of the electric motor current corresponding to the electric motor speed graph of FIG. 7, and FIG. 8 is a view showing a time change graph of the agitator speed obtained from the electric motor speed and the current of FIGS. 6 and 7. . 10 …… washing machine, 12 …… frame, 14 …… panel, 16 …… box,
18 ... Lid, 20 ... Back console, 22 ... Timer dial, 24 ... Temperature selector, 26 ... Vessel, 28 ... Perforated basket, 30 ... Stirrer, 32 ... Electric motor, 34 ... … Drive mechanism,
38 …… Pulley mechanism, 40, 42 …… Bracket structure, 44 ……
Drive pulley, 46 ... Driven pulley, 48 ... Belt, 50 ...
… Spring clutch, 52 …… Planetary gear housing, 54 …… Deceleration drive mounting frame, 56 …… Upper body, 58 …… Spiral blade, 60 …… Lower stirring section, 62 …… Flexible blade, 80 ...... Electronic control circuit, 82 …… Power supply circuit, 84 …… Output drive circuit, 86
...... Logic circuit, 88 …… Lead wire, 90 …… Half wave rectifier, 9
2, 132 …… Zener diode, 94 …… Filter condenser, 96, 98, 100, 102 …… Power triac, 104, 106
...... Transistor amplifier, 108 …… Timer, 110 …… Output conductor, 112,122 …… Inverter, 116 …… Flip-flop, 122,124 …… NAND gate, 130 …… Transistor, 134,136 …… RC element ．

Claims (23)

[Claims] 1. A drive device for an automatic washing machine having an agitator installed in a washing tub, wherein a high slip electric motor installed in the automatic washing machine, and the high slip motor for rotating the agitator. A drive unit connecting the electric motors; and a control circuit connected to operate the high slip electric motors in first and second opposite directions, the control circuit in the first and second directions And a means for alternating the electric motor operation, the alternating means comprising:
A driving device, characterized in that, during the operation of the electric motor, the operation of the electric motor is interrupted at each reversal of the directions so as to perform a substantially sinusoidal rotational motion. 2. An automatic washing machine for washing fabric products in a water tub, a washing machine cabinet, a washing tub mounted in the cabinet for receiving articles to be washed in the water tub, and the laundry An energy absorbing stirrer rotatably mounted in the tub and connectable to the washing tub and the article to be washed; a low starting torque electric motor mounted in the washing machine cabinet; and rotating by the electric motor. A reduction drive having a connected high speed input and a low speed output selected to rotate the stirrer; and at a periodic rate to operate the motor primarily at low torque starting speeds. An automatic washing machine having a control means for reversibly operating an electric motor. 3. The automatic washing machine according to claim 2, wherein the low starting torque electric motor is a fixed split capacity electric motor. 4. The automatic washing machine according to claim 2, wherein the energy absorbing stirrer is provided with flexible blades. 5. The automatic washing machine according to claim 2, wherein the electric motor is deenergized for a predetermined time before the control means reverses the operation of the electric motor. 6. An automatic washing machine as claimed in claim 2, wherein the stroke rate of the agitator driven by the electric motor is between 60 and 70 strokes per minute. 7. The automatic washing machine according to claim 2, wherein the range of travel of the agitator when driven by an electric motor is between 120 ° and 230 °. 8. An automatic washing machine as set forth in claim 7, wherein the stroke angle is between 190 ° and 200 °. 9. The method of claim 1, wherein the control means comprises a drive circuit connected to drive the electric motor, the control means generating a series of substantially square wave pulses for operating the drive circuit. An automatic washing machine according to claim 7. 10. The automatic washing machine according to claim 2, wherein the control means is an open loop control means. 11. A first means connected to the control means so as to alternately bias the field of the electric motor.
And a drive circuit having a second triac, means and timers for generating a series of spaced pulses at first and second outputs respectively connected to the first triac and the second triac. The automatic washing machine according to claim 2, wherein the automatic washing machine is a control circuit including a logic circuit provided therein and a power supply connected to supply power to the logic circuit. 12. The automatic washing machine according to claim 2, wherein the deceleration drive unit includes a planetary gear mechanism. 13. A vertical axis type automatic washing machine for selecting cloth products in an aquarium, the cabinet having an openable door, and the concentric inside the cabinet for receiving the aquarium and articles to be washed. A washing tub and a basket attached to the washing tub, a stirrer with blades that is rotatably mounted in the washing tub and the basket and engages with the water tub, and a high speed input end connected to rotate the stirrer. And a deceleration driving unit having a high speed output end, and a first deceleration driving unit connected to drive the high speed input end of the deceleration driving unit to operate in first and second opposite directions.
And a high-slip electric motor having a second field, and a control circuit connected to operate the high-slip electric motor in two opposite directions, wherein the control circuit comprises the first field of the electric motor. A first active element connected to the magnet, a second active element connected to the second field of the motor, a timer having an output for delivering a series of timer pulses, the timer output Connected to the ends of the first and second triggers
A logic circuit having a first and a second logic output for generating a pulse, the first logic output having the first trigger pulse for the first active element of the motor. A first magnetic field is connected to the first active element to drive the motor in the first direction, and the second logic output is connected to the second trigger pulse. A vertical axis automatic washing machine in which a second active element is connected to the second active element so as to activate the second field of the electric motor to operate the electric motor in the second direction. . 14. A logic circuit comprising: a flip-flop having an input connected to receive the timer output, an inverting output, and a non-inverting output; and a first output connected to the timer output. A first logic gate having an input end, a second input end connected to the non-inverting output end of the flip-flop, and an output end forming an output end of the logic circuit, and connected to the timer output end. A second logic gate having a first input, a second input connected to the inverting output of the flip-flop, and an output forming the second logic output. Claim 13
Vertical axis type automatic washing machine according to the item. 15. A logic circuit is provided to the first and second logic gates to interrupt the first and second trigger pulses for a predetermined time when power is first applied to the logic circuit. A method as set forth in claim 14 including means for connecting time delays and means for applying power to said logic circuit.
Vertical axis type automatic washing machine according to the item. 16. The drive unit according to claim 1, wherein the means for alternating the operation of the electric motor comprises a drive circuit for alternately energizing the field of the electric motor. 17. A means for altering the operation of the electric motor comprises a logic circuit having timer means for generating a series of spaced pulses at first and second outputs connected to the drive circuit. The drive device according to claim 16. 18. A drive circuit comprising two pairs of power triacs for alternatingly energizing a field of an electric motor, said triac pairs being controlled by first and second transistor amplifiers, respectively. The drive unit according to Item 17. 19. The logic circuit comprises a flip-flop that receives an inverted signal from a timer, the flip-flop acting as a switch to generate an alternating signal to the first and second NAND logic gates, The timer signal is supplied to the NAND gate in a non-inverted form to decode the outputs of the timer and the flip-flop,
And a second NAND gate connected to the first and second transistor amplifiers, respectively.
The drive device according to the item. 20. A first circuit connected to the control circuit so as to alternately bias the field of the electric motor.
And a drive circuit having a second triac, and means and a timer for generating a series of spaced pulses at first and second outputs connected to the first triac and the second triac. The driving device according to claim 1, comprising a logic circuit and a power supply connected to supply power to the logic circuit. 21. An automatic washing machine according to claim 2, wherein the control means for reversibly operating the electric motor comprises a drive circuit for alternately energizing the field of the electric motor. 22. A logic circuit, wherein the control means for reversibly operating the motor comprises a timer and a means for generating a series of spaced pulses at first and second outputs connected to the drive circuit. The automatic washing machine according to claim 21, further comprising: 23. Vertical according to claim 13, wherein said first and second active elements comprise first and second triacs connected to said first and second fields. Axis type automatic washing machine.